LHASA -- More than 80 percent of villages in southwest China's Tibet Autonomous Region have access to the Internet, according to the latest statistics.

By the end of December 2015, 4,208 villages had broadband, accounting for 80 percent of the total, up from 19.6 percent five years ago, said Chochi, head of the regional telecommunications department.

The length of optical cable has doubled in five years to reach 114,000 kilometers. About 1.87 million households, or 59 percent of the total, are now able to use the Internet, he said.

The plateau region is known as "the roof of the world" due to its average altitude of over 4,000 meters, and building telecommunications infrastructure is difficult and costly.

Telecom operators lowered Internet costs in Tibet in 2015, boosting e-commerce.

The remote Ngari Prefecture is one of the most sparsely populated places in the world. People in the prefecture's Tsochen County started doing e-commerce in 2014.

"By the end of 2015, revenue from e-commerce topped 4.1 million yuan (about $629,800)," said Phubu Cering, head of the commerce bureau of Tsochen. The county's population was about 13,200.

"Nine people in the county registered on Alibaba's trading platform, Taobao, to sell Tibetan incense, beef and cashmere products," Phubu Cering added.

According to Chochi, the region will expand its 4G network in 2016.